Solved Problems
Database Design
Sample Q1
Draw an ER diagram for the following application from the manufacturing
industry:
1. Each supplier has a unique name.
2. More than one supplier can be located in the same city.
3. Each part has a unique part number.
4. Each part has a colour.
5. A supplier can supply more than one part.
6. A part can be supplied by more than one supplier.
7. A supplier can supply a fixed quantity of each part.
Answer Q1
Sample Q2
The Motor Vehicle Branch administers driving tests and issues driver’s licenses.
Any person who wants a driver’s license must first take a learner’s exam at any
Motor Vehicle Branch in the province. If he/she fails the exam, he can take
the exam again any time after a week of the failed exam date, at any branch.
If he passes the exam, he is issued a license (type = learner’s) with a unique
license number. The person may take his driver’s exam at any branch any time
before the learner’s license expiry date (which is usually set at six months after
the license issue date). If he passes the exam, the branch issues him a driver’s
License
Create a E-R diagram following these steps.
1. Find out the entities in the spec.
2. Find out the relationships among the entities.
3. Figure out attributes of the entities and (if any) of the relationships.
4. Figure out constraints between entities and relationships.
5. Check to see if you miss anything in spec.
Answer Q2
Answer Q2
Sample Q3
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List the functional Dependencies
Answer Q3